Yes, there is a recognized deformity at the base of the 5th metatarsal called bunionette deformity (tailor's bunion)
Bunionette deformity is a forefoot protuberance located laterally, dorsolaterally, or plantarlaterally along the fifth metatarsal head and base, resulting from a multifactorial anatomic interplay between fifth metatarsal bony morphology and forefoot soft-tissue imbalance. 1
Anatomic Characteristics of the Deformity
The deformity involves metatarsus quintus valgus (outward deviation of the fifth metatarsal) combined with varus deformity of the fifth toe with subluxation of the metatarsophalangeal joint 2
The bony prominence can manifest in different locations along the fifth metatarsal, with classification systems (such as Shimobayashi) recognizing Types I through V based on the specific anatomic pattern 3
Friction between the bony prominence, soft tissue, and constrictive footwear results in keratosis, inflammation, pain, and potential ulceration 1
Clinical Significance
This is a common foot disorder that warrants proper evaluation when symptomatic 1, 4
The deformity can be assessed radiographically using the fourth-to-fifth intermetatarsal angle, which averages around 12 degrees in symptomatic patients before correction 3
In diabetic patients with neuropathy and foot deformities, special attention must be paid to offloading areas overlying bony deformities to prevent ulceration 5
Diagnostic Approach
Standard three-view radiographs (anteroposterior, lateral, and mortise) are necessary to properly evaluate the bony anatomy and confirm the deformity 6, 7
For non-painful swelling at the base of the fifth metatarsal, MRI is the preferred advanced imaging modality if radiographs are negative, as it can detect occult fractures, accessory ossicles, bone marrow edema, and soft tissue pathology 7
Accessory ossicles occur in 4% of asymptomatic subjects and must be differentiated from true deformity through clinical correlation 7